Abstract
Two cloned rat astrocytoma cell lines, 36 B-10 and 40 A-2, maintained in vitro were treated with 1 mM dibutyryl cyclic AMP. This treatment induced arborization of cellular processes and rounding-up of cell bodies in both cell lines and was associated with increased microvillous development in 40 A-2. There were not detectable concomitant changes in either (a) the quantity or organization of microtubules or 80-100 nm microfilaments, or (b) the intensity of glial fibrillary acidic protein indirect immunofluorescence staining.